The present invention relates generally to a method and a device for transferring a flow of data by a first telecommunication device to a second telecommunication device.
In wireless cellular telecommunication networks, one transmitter transfers data to one receiver via one radio channel. When the receiver is moving away from the transmitter, the network routes data to the receiver via another transmitter enabling a handover between the two transmitters.
In wireless cellular telecommunication networks using Code Division Multiple Access scheme, a specific variant of handover has been developed, which is called soft handover. In such situation, the same data is transmitted by different transmitters in the vicinity of a mobile terminal which includes multiple receivers. The mobile terminal combines the energies of the signal received from the multiple transmitters in order to increase the quality of the received signal.
In a variant of soft handover, called Site Selection Diversity Transmission, the mobile terminal can select which transmitter can transmit the data. The interference level is reduced as only the best transmitter transmits signal with the minimum power level needed to reach the receiver. In case of independent fading over the multiple transmitters, SSDT can be an effective technique to avoid fading and degradation of signal level in handover areas.
SSDT requires that the scheduling of data over the multiple transmitters is controlled by a central entity called Radio Network Controller. The Radio Network controller transmits the data to each transmitter, even if data need not to be used by the transmitter. That method produces significant overhead between RNC and transmitters. It has to be noted here that the SSDT can not be applied as such in the Third Generation Project/Long Term Evolution 3GPP/LTE network under discussion, where the network no longer deals with a central entity like a RNC.
Furthermore, in classical wireless cellular telecommunication network, the data transferred between transmitters and receivers are encrypted in order to warrant the privacy of the transferred data.